The olfactory membranes in your nose are densely packed with smell receptors. These receptors come in some 400 different subtypes; complex odors like that of rose petals can waft around 175 distinct kinds of odor molecules in the direction of your nose. In other words, the number of discrete odors we can perceive runs to the tens of thousands. No wonder scientists had thought that the whole smell arrangement was basically random.
But research by Prof. Noam Sobel and his team in the Weizmann Neurobiology Department is bringing our noses into line with our other sensory organs. The arrangement…